Automatically switched camera systems (ASCS) have mechanical or electronic pan, tilt, zoom video cameras and heuristic means for deciding when to move the camera, i.e., pan, tilt, and/or zoom the camera, in response to audio or some other automatic driving mechanism. Typical ASCSs employ audio driving mechanisms which are implemented with one or more microphones. An ASCS driven by an audio driving mechanism pans, tilts, and/or zooms the camera toward the sound of a speaker's voice. For a more detailed description of an ASCS, see commonly-assigned, copending U.S. patent application Ser. No. 09/759,486, entitled “Method and Apparatus for Determining Camera Movement Control Criteria”, filed on Jan. 12, 2001.
Existing ASCSs, used in applications such as videoconferencing, include various means for indicating who the current or main subject of the ASCS is. For example, the current or main subject can be displayed in a monitor or a picture-in-picture window within a main video conference display. The current or main subject can also be indicated by the turning the mechanical or electronic pan-tilt-zoom camera of the ASCS in the direction of the subject.
Although existing ASCSs indicate who the current or main subject is, such systems do not provide any type of indication of who the next subject will be. This drawback makes it virtually impossible for the next subject to prepare to become the focus of attention of the ASCS or alter their behavior so that they do not become the focus of attention of the ASCS.
Accordingly, an ASCS is needed which is capable of notifying the next subject of the system that he or she is about to be focused on.